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Localized Event Explained-Partially Charred Surface

  • James E. SmallEmail author
Chapter
  • 273 Downloads
Part of the SpringerBriefs in Fire book series (BRIEFSFIRE)

Abstract

  • Visual Artifact

A partially charred surface area is found.
  • Evaluation

In order to burn away PCB surface material several things must be present:
  1. (1)

    A moist environment for several min at a time.

     
  2. (2)

    Repeated moist environment episodes in the presence of voltage and current.

     
  3. (3)

    An external supply of energy for a 1.574 mm thick FR4 laminate in the neighborhood of 39 J for 9 s to ignite and 47 J to sustain a flame for 11 s that is capable of carbonizing the material. For a 1.574 mm thick CEM-1 laminate this can occur with 27 J for 6 s to ignite and 157 J to sustain a flame for 35 s that is capable of carbonizing the material. See experiments #5, #9a and #9b of Chap.  14 for comparative details.

     

Keywords

Opposite Polarity Conductive Path Visual Artifact Ample Supply Exposed Copper 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Reference

  1. 1.
    Bumiller, E and Hillman, Hillman, Dr. Craig, “Review of Models for Time-to-Failure Due to Metallic Migration Mechanisms”, Last accessed June, 2016, http://www.dfrsolutions.com/uploads/white-papers/Time-to-Failure_Metallic_Migration.pdf

Copyright information

© The Author(s) 2017

Authors and Affiliations

  1. 1.Fort WayneUSA

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